About Me

Sunday, 15 December 2013

China successfully landed an unmanned vehicle on the Moon.The Chang'e-3 mission is named after the goddess of the Moon in Chinese mythology and the rover vehicle is called Yutu (Jade Rabbit) after her pet.Chang'e-3 landed on a volcanic site Sinus Iridum which is part of Mare Imbrium.This landing makes China the third country after USA and Soviet Union to have landed unmanned spacecrafts to the Moon.Good luck to them...

e-waste often contains substances that are harmful to humans and the environment if not properly treated. Effective rules for monitoring and treating e-waste are required for its safe disposal.

e-waste is a growing problem. According to a UN report, the amount of e-waste is set to grow by more than 30% by 2017. The world produced 54 million tons of e-waste in 2012 with the usual suspects, US and China, taking top places.

By 2017, refrigerators, TVs, mobile phones, DVDs, computers, monitors, e-toys and other products on the dump heap with a battery or electrical cord would fill a line of 40-ton trucks end-to-end on a highway covering three quarters of the Equator!

Lot of the e-waste finds its way to underdeveloped countries where it is estimated that two-thirds of the recycling is done by unorganized groups. Because such groups do not follow safe recommended practices, not only toxic substances pollute air, soil and water but the people around are exposed to dangerous gases etc.

Electronic gadgets contain valuable minerals like gold, silver, platinum, rare-earth elements etc. and loss of these in unregulated and inefficient recycling of e-waste represents a serious loss of resources.

What we need is good international regulations for safe and efficient handling of e-waste. The increasing amounts of e-waste is a reality and we just need to learn to cope with it without damaging our health and environment further.

Tuesday, 10 December 2013

Common
sense is what we humans live by – it is kind of wisdom gained from experience
over many generations. Humans experience the world through the
five senses, but importantly we also use our intelligence to perform cause and effect
analysis of what has been happening around us to understand how the world behaves. Common sense has worked very
well and has ensured the survival of the human race; particularly, in the
avoidance of dangerous and harmful situations.
Human societies evolved to preserve and enhance the species. Shared knowledge and effort proved useful in
meeting adverse situations and quality of life improved rapidly as humans
started to live together in social groups. Survival of human societies is a multifaceted situation;
they not only have to guard against the hostile physical environment around
them but also against other fellow humans who are driven by greed, violence and
other undesirable traits. Humans have
always enjoyed exercising power and control over others around them. This is a
classic example of conflicting requirements – living in societies is beneficial
but at the same time exposes one to potentially dangerous elements of oppression
and exploitation. How humans dealt with
this is fascinating and will be discussed in a future blog.How
does our common sense relate to the laws of nature is what we wish to look at
first. The difference is in the scope of
the evidence available.Laws of nature are
deduced from experimental observations at all possible levels of space and
time. As human ability improves to
expand such observations to wider regions of space and time, laws of nature are
modified or even replaced by a different set of laws. Fine-tuning of the laws is fundamental to
their authenticity and acceptance. The
current set is the best available to make sense of what the empirical evidence
tells us. Common
sense is much more restricted in terms of empirical evidence at its disposal. Without technological aids - and most human
experiences have been in such conditions - humans really occupy a small region
roughly in the middle of space-time expanse.
Their experiences are limited in size, speed, time, colour, frequency
etc. Quantitatively: We experience

Physical dimensions from ~0.01 mm to a few hundred km. Speeds
vary from rest to a few tens of km/hour.Time
is restricted to our reaction time of the order of 10 ms to a few hundred
years.Colour is perceived in the narrow wavelength range of 0.4 to 0.8 micron (1 micron = 0.001 mm)Perception of sound is limited to frequencies less than about 20 kHz.Animal
species do better in colour and sound perception due to the evolutionary need
to protect themselves against predators etc.Humans
mainly perceive the world around them through light which travels at the
fantastic speed of 300,000 km per second; this gives the feeling of
instantaneous communication – things are happening as we see them.Natural
phenomena like rain, thunder, lightening, tides, storms, earthquakes, motion of
heavenly bodies, infectious/mental and other diseases etc. were mediated by
causes outside the range of human perception.
Theories and explanations were put forward – of course different in
different societies – to make sense of such events. This can give rise to beliefs, customs, rituals, superstitions etc. We shall return to this later.Limited
scope of human experience, nevertheless, provided some quite sensible and
workable theories about the way the world operates – kind of ‘limited’ laws of
nature. In good true scientific spirit a
law would get modified when the evidence against it became overwhelming. Sometimes it would require great sacrifices as
changing a law might encumber on the interests/dogma of the
powerful in the society. Situation
started to improve about 500 years ago with the acceptance that experiment
based evidence could not be ignored and must be taken into account in
formulating so called laws of nature.
Technological advances helped in removing many of the limits to
observations – in space, time and other areas.
Common sense inspired laws of nature started to be replaced by the new
physics at the turn of the 20th century and in the short span of 25
years the acceptance of the new laws of relativistic and quantum physics was
overwhelming. While
common sense laws are arrived at through observations, mostly visual, and rely
on the behaviour of matter around us at the macroscopic scale of dimensions
greater than about 1 micron (0.001 mm), laws of nature (physics) are determined
in the way elementary particles, typically of dimensions less than 0.001 micron,
interact with each other. These
interactions are of four types:

gravitational (G),

electromagnetic (EM),

strong
nuclear (SN) and

weak nuclear (WN).

G
and EM are long range and affect matter at all distances. SN and WN are relevant only at nuclear
dimensions with distances of the order of a billionth of a micron or less! Chemical and biological properties are determined by EM forces acting between atoms and molecules at distances of the order of 0.001 microns and may not be properly understood
through evidence from everyday experience. Old theories based on human experiences have been unable to make good sense of chemistry and life sciences.Motion
of heavenly bodies is governed by gravitational forces but mostly involves
distances far greater than our senses can be sensitive to. That is why there has been so much confusion
about this subject in historical accounts. Newton's laws of gravitational attraction
explained the way heavenly bodies are organised in the
sky but a proper understanding of the Universe had to wait for the theories of relativity and the development of nuclear sciences.

The world of atoms and nuclei was latent to our ancestors as the distances involved
were unimaginably small and even their existence could not be contemplated. Understanding
the true nature of atoms and nuclei only started at the turn of the 20th
century and this has created the atmosphere in which modern industry could start. Nuclear energy, Nanotechnology, Computers,
Biotechnology, Space Exploration all owe their success to the laws of nature
enunciated through empirical evidence acquired through development in
technology in the 19th and 20th centuries.
Without this mind-set, modern industry would not even be science fiction.Another
interesting aspect of this discussion is the emergence of paradoxes. A language that is weakly developed will be
unable to describe a situation that is highly complex – the vocabulary is just
not there. A good example of a paradox
is the wave-particle duality in classical physics (mostly based on common sense
observations). In our daily lives we see
objects behave like material particles or as undulating waves in motion. We do not have objects that switch between
being waves and particles at different times.
This was the situation until the end of the 19th century when light was
observed to exhibit properties akin to waves in some experiments but behaved
exactly like a stream of particles in others.
The situation was resolved and explained by quantum description of light
in 1925. Now, we know that everything in
the universe shows wave-particle duality and it is just our attempt to
classify things as either waves or particles that is flawed. We are using the wrong language for our
description.It
is not that there are no paradoxes in the modern theories. There are many and this simply points to the
fact that, while we have a much better understanding of the world we live in,
we have more to learn and the laws of nature will be rewritten differently
in the future.